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Date: Fri, 19 Apr 2013 00:55:20 -0400
Message-ID: <CA+8xBpf0Xsg7-zGSpk0jUZifVqg+gFCbj-+CaagsnD1cpN8nLA@mail.gmail.com>
From: Jeff Garzik <jgarzik@exmulti.com>
To: John Dillon <john.dillon892@googlemail.com>
Content-Type: text/plain; charset=ISO-8859-1
Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Anti DoS for tx replacement
Precedence: list

On Fri, Apr 19, 2013 at 12:38 AM, John Dillon
<john.dillon892@googlemail.com> wrote:
> I understand that Gavin has spent effort on security efforts against
> small-scale attackers. It's the fact that he is so dismissive of the
> threat that large attackers play that is what bothers me. But if I am
> being divisive I understand.

I cannot speak for Gavin, but speaking more generally, large attackers
tend to belong in a thought-class all their own.

Example 1:  if some super-ASIC miner arises with 90% of hash power,
and he starts behaving in a way contrary to the useful functioning of
bitcoin, the community might decide to change the PoW algorithm at
block height N.

Example 2:  If someone large DDoS's the entire P2P network, which is
possible, manual intervention would be required to straighten out the
mess.

In each case, it's more about the community's mutual defense actions
than any prepared defense.

Speaking even more generally, bitcoin may be a billion-dollar
invention, but that doesn't mean it has any funding for network
defense!  Unless cost structures and user attitudes change,
development and deployment of major defense strategies seems unlikely.
 Which implies the community will simply wait for a [attack |
explosion | crisis], and then hope we can unwind/repair the damage
afterwards.

-- 
Jeff Garzik
exMULTI, Inc.
jgarzik@exmulti.com